Mineral cutter system

ABSTRACT

A mineral cutter system comprises a pick box ( 3 ) adapted to be secured, by welding, to a powered drum or disc ( 2 ) and having a bore ( 4 ) to receive a replaceable sleeve ( 5 ) having a collar ( 8 ) and also a circular section bore ( 15 ) to receive a circular section shank ( 16 A or  16 B) of a replaceable mineral cutter pick ( 17 A or  17 B), the bore ( 4 ) of the pick box ( 3 ) incorporating at least one flat ( 6 ), and the sleeve ( 5 ) being provided with at least one external flat ( 7 ) to engage the flat ( 6 ) whereby the sleeve ( 5 ) is non-rotatable with respect to the box ( 3 ), and the collar ( 8 ) of the sleeve ( 5 ) being both recessed (at  21 ) to accommodate a circular collar ( 20 ) of a point attack pick ( 17 A), and slotted to provide opposed abutment faces ( 23 ) to engage a pair of opposed flats ( 27 ) of a non-rotatable, semi-forward attack pick ( 17 B). The invention also includes a rotary drum or disc ( 1 ) provided with this cutter system and with either a rotatable or non-rotatable pick ( 17 A or  17 B).

FIELD OF THE INVENTION

This invention relates to a mineral cutter system, of the known kind comprising a sleeved box, the sleeve receiving a pick shank, and to a rotary drum or disc provided with such a cutter system.

BACKGROUND OF THE INVENTION

A widely used system for mineral cutting/winning operations, or for road planning as part of road re-surfacing operations, comprises a pick box welded on to a power driven drum or disc carrying say fifty boxes, with the box having a bore to receive a replaceable, collared sleeve, which in turn has a bore to receive a circular section shank of a mineral cutter pick, the pick, when worn or damaged being removed and replaced, and similarly the sleeve, the objective being to protect the box from damage. Should a certain number of boxes become damaged, box replacement is unavoidable, and if the drum or disc is operating in a UK coal mine, regulations demand that the drum or disc be brought to the surface, or possibly to a safe area, for removal of the damaged box(es) for replacement boxes to be welded in their place(s).

Some picks operate on the so-called point attack principle, in which case an ability for the pick to be free to rotate about its longitudinal axis is desirable.

Other picks operate on a forward attack, or semi-forward attack principle, requiring a specific, non-rotatable orientation.

OBJECT OF THE INVENTION

A basic object of the invention is the provision of an improved mineral cutter system, of the sleeved kind able to accommodate either a point attack pick, or a semi-forward attack pick.

SUMMARY OF A FIRST ASPECT OF THE INVENTION

According to a first aspect of the present invention there is provided a mineral cutter system comprising a pick box adapted to be secured, by welding, to a powered drum or disc and having a bore to receive a replaceable sleeve having a collar to limit the penetration of the sleeve into the bore of the pick box, the sleeve having a circular section bore to receive a circular section shank of a replaceable mineral cutter pick, characterised in that the bore of the pick box incorporates at least one flat, and the sleeve is provided with at least one external flat adapted, when fitted into the bore of the pick box, to engage the flat of the bore, whereby the sleeve is non-rotatable with respect to the box, and the collar of the sleeve is both recessed to accommodate a circular collar of a point attack pick, and slotted to provide opposed abutment faces to engage a pair of opposed flats of a non-rotatable, semi-forward attack pick.

ADVANTAGE OF THE INVENTION

Either a point attack pick or a semi-forward attack pick may be fitted in the same sleeve and pick box in accordance with the invention, providing dual cutting modes and hence greater flexibility of use of the same drum or disc.

PREFERRED OR OPTIONAL FEATURES

The bore of the pick box is provided with two opposed flats.

The bore of the pick box is provided with four opposed flats.

The bore of the pick box is provided with six opposed flats.

The bore of the pick box is provided with eight opposed flats.

The sleeve is provided with a corresponding number of flats to that of the bore.

The sleeve is provided with a circumferential groove to receive a retaining device to engage the bore of the pick box to prevent inadvertent extraction of a sleeve from its receiving bore.

The retaining device is of synthetic plastics.

The retaining device is provided with multiple deformable ribs.

The shank of the pick, whether point attack or semi-forward attack is provided with a retaining device.

The retaining device of the shank is a spring steel, split collar.

The end of the pick box remote from the collar of the sleeve is open to expose an end of the sleeve and an end of a pick, with the tolerances between the bore of the pick box and the sleeve, and between the bore of the sleeve an the pick shank, are such that a worn pick may be knocked out of the sleeve, and a worn sleeve may be knocked out of the pick box.

SUMMARY OF A SECOND ASPECT OF THE INVENTION

According to a second aspect of the present invention of independent significance, there is provided a rotary drum or disc provided with a plurality of pick boxes, secured by welding, to its external periphery, each pick box having a bore in which is fitted a replaceable sleeve having a collar to limit the penetration of the sleeve into the bore of the pick box, the sleeve having a circular section bore in which is fitted a circular section shank of a replaceable mineral cutter pick, the bore of the pick box incorporating at least one flat, and the sleeve is provided with at least one external flat adapted, to engage the flat of the bore, whereby the sleeve is non-rotatable with respect to the box, and the collar of the sleeve is recessed and accommodates a circular collar of a point attack pick.

SUMMARY OF A THIRD ASPECT OF THE INVENTION

According to a third aspect of the present invention of independent significance, there is provide a rotary drum or disc provided with a plurality of pick boxes, secured by welding, to its external periphery, each pick box having a bore in which is fitted a replaceable sleeve having a collar to limit the penetration of the sleeve into the bore of the pick box, the sleeve having a circular section bore in which is fitted a circular section shank of a replaceable mineral cutter pick, the bore of the pick box incorporating at least one flat, and the sleeve is provided with at least one external flat adapted, to engage the flat of the bore, whereby the sleeve is non-rotatable with respect to the box, and the collar of the sleeve is slotted to provide opposed abutment faces and engages a pair of opposed flats of a non-rotatable, semi-forward attack pick.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of a mineral cutter system in accordance with the invention provided with a point attack pick.

FIG. 2 is a view in the direction of arrow Q.

FIG. 3 is a view in the direction of arrow T.

FIG. 4 is a view in the direction of arrow E.

FIG. 5 is a section on the line P-P of FIG. 1; and

FIGS. 6 to 10 correspond to FIGS. 1 to 5 but show a semi-forward attack pick fitted into the same sleeve and pick box of FIGS. 1 to 5.

DETAILED DESCRIPTION OF THE DRAWINGS

On the external periphery 1 of a power driven, rotary drum or disc 2, are welded, at predetermined locations, a plurality of pick boxes 3, each having a bore 4 of hexagonal profile and hence provided with six flats 6 to receive a replaceable sleeve 5 of corresponding hexagonal profile, having six flats 7 so that, when inserted, the sleeve 5 is non-rotatable with respect to the box 3. The sleeve 5 also has a collar 8 to seat on an upper edge 9 of the pick box 3, to fix the depth of penetration of the sleeve 5 into the bore 4.

The collar 8 is provided with two opposed grooves 10 so that the collar 8 does not impede a spray of water from a nozzle 11 carried in a nose 12 of the pick box 3. The provision of two grooves 10 enables a sleeve 5 that is worn at one side to be removed, rotated through 180°, and replaced.

The exterior of the sleeve 5 is provided toward its end distal from the collar 8, with a groove 13 to receive a retaining device in the form of a multi-ribbed insert 14 of synthetic plastics adapted to frictionally engage the bore 4, to discourage inadvertent extraction of a sleeve 5 from its box 3 e.g. during occasional reverse rotation of the drum or disc 2.

The sleeve 5 has a circular section bore 15 to receive a circular section shank 16A or 16B of a replaceable, mineral cutter pick 17A or 17B having a carbide tip 18A or 18B brazed into a recess in the terminal end of a frusto-conical head 19A of the pick 17A, whilst a circular collar 20 separates the head 19A from the shank 16A.

The sleeve collar 8 is also provided with a circular recess 21 defined by a part-circular walls 22, the latter being slotted to provide four abutment faces 23.

In the embodiment of FIGS. 1 to 5, the pick 17A is of a so-called “point attack” type, whereby rotation of the pick 17A, in use, is permitted, the circular collar 20 fitting within the recess 21, and the flats 23 are redundant. The exterior of the shank 16A, distal from the tip 18A is provided with a groove 24 to receive a retaining device in the form of a split steel ring 25 adapted to engage a shallow groove 26 in the bore 15.

In the embodiment of FIGS. 6 to 10, the pick 17B is of a so-called “semi-forward attack” type, which requires a specific orientation and hence is required to be non-rotatable within the sleeve. For this purpose head 19B of the pick 17B is provided with flats 27 to engage the flats 23 of the collar 8, and the part-circular walls 22 are redundant.

In accordance with the second aspect of the invention, a point attack pick 17A is fitted into each sleeve 5, as illustrated in FIGS. 1 to 5.

In accordance with the third aspect of the invention, the same sleeve 5 receives a semi-forward attack pick 17B provided with opposed flats 27 to engage the flats 17, as illustrated in FIGS. 6 to 10. 

1. A mineral cutter system comprising a pick box adapted to be secured, by welding, to a powered drum or disc and having a bore to receive a replaceable sleeve having a collar to limit penetration of said sleeve into said bore of said pick box, said sleeve having a circular section bore to receive a circular section shank of a replaceable mineral cutter pick, characterised in that said bore of said pick box incorporates at least one flat, and said sleeve is provided with at least one external flat adapted, when fitted into said bore of said pick box, to engage said flat of said bore, whereby said sleeve is non-rotatable with respect to said box, and said collar of said sleeve is both recessed to accommodate a circular collar of a point attack pick, and slotted to provide opposed abutment faces to engage a pair of opposed flats of a non-rotatable, semi-forward attack pick.
 2. A system as claimed in claim 1, wherein said bore of said pick box is provided with two, four, six or eight opposed flats.
 3. A system as claimed in claim 2, wherein said sleeve is provided with a corresponding number of flats to that of said bore.
 4. A system as claimed in claim 1, wherein said sleeve is provided with a circumferential groove to receive a retaining device to engage said bore of said pick box to prevent inadvertent extraction of said sleeve from its receiving bore.
 5. A system as claimed in claim 4, wherein said retaining device is of synthetic plastics.
 6. A system as claimed in claim 4, wherein said retaining device is provided with multiple deformable ribs.
 7. A system as claimed in claim 1, wherein said shank of said pick, whether point attack or semi-forward attack, is provided with a retaining device.
 8. A system as claimed in claim 7, wherein said retaining device of said shank is a spring steel, split ring.
 9. A system as claimed in claim 1, wherein an end of said pick box remote from said collar of said sleeve is open to expose an end of said sleeve and an end of a pick, with tolerances between said bore of said pick box and said sleeve, and between said bore of said sleeve and said pick shank, being such that a worn pick may be knocked out of said sleeve, and a worn sleeve may be knocked out of said pick box.
 11. A rotary drum or disc provided with a plurality of pick boxes, secured by welding, to its external periphery, each said pick box having a bore in which is fitted a replaceable sleeve having a collar to limit penetration of said sleeve into said bore of said pick box, said sleeve having a circular section bore in which is fitted a circular section shank of a replaceable mineral cutter pick, said bore of said pick box incorporating at least one flat, and said sleeve being provided with at least one external flat adapted, to engage said flat of said bore, whereby said sleeve is non-rotatable with respect to said box, and said collar of said sleeve is recessed and accommodates a circular collar of a point attack pick.
 12. A rotary drum or disc provided with a plurality of pick boxes, secured by welding, to its external periphery, each said pick box having a bore in which is fitted a replaceable sleeve having a collar to limit penetration of said sleeve into said bore of said pick box, said sleeve having a circular section bore in which is fitted a circular section shank of a replaceable mineral cutter pick, said bore of said pick box incorporating at least one flat, and said sleeve being provided with at least one external flat adapted, to engage said flat of said bore, whereby said sleeve is non-rotatable with respect to said box, and said collar of said sleeve is slotted to provide opposed abutment faces to engage a pair of opposed flats of a non-rotatable, semi-forward attack pick. 